title: Design and fabrication of a supermirror with smooth and broad response for hard x-ray telescopes.
abstract: We present our design and fabrication scheme of a supermirror for hard x-ray telescopes to improve the performance of reflection. Supermirrors are designed to achieve target reflectivity profiles with small ripples in the interesting energy range with a limited number of layer pairs. Starting from conventional design methods, we optimized the thickness distribution of the structure using a numerical approach with the merit function established for this application. As an example, a platinum-carbon supermirror structure of 123 layer pairs with a varying d-space of 2-6 nm was designed to enhance the reflectivity in the energy range from 11 to 55 keV with a flat top at a grazing angle of 0.28 deg. The multilayer thus designed was deposited on a float glass by our DC magnetron sputtering system. The reflectivity profile was successfully measured to be ~20% with little oscillation in all energy band of interest.
authors.forename: Youwei
authors.initials: Y
authors.lastname: Yao
authors.forename: Hideyo
authors.initials: H
authors.lastname: Kunieda
authors.forename: Hironori
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tamura
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Miyata